Detectable Warning Surfaces

Also called truncated domes, detectable warnings, tactile ground indicators and tactile pavers, detectable warning surfaces were first used over 35 years ago by countries such as Japan, the United Kingdom and Australia. The United States instituted detectable warnings requirements in 1990 with the passage of the Americans with Disabilities Act (ADA 4.29).

Detectable warnings provide a distinctive surface pattern of truncated domes that serves as a "tactile" cue to persons with vision impairments, alerting them that they're walking into a hazardous vehicular area or change of grade. Detectable warnings are installed on crosswalks, wheelchair ramps, by reflecting pools and on transit platforms. Detectable warnings may also be installed on stairway landings and escalator landings.